Former Canadian technology giant Nortel Networks Corp. has auctioned off all its remaining patents to a consortium of software companies for $4.5 billion US.

The consortium consists of Waterloo, Ont.-based Blackberry maker Research In Motion, Apple, EMC, Ericsson, Microsoft and Sony. RIM says its portion of the purchase is approximately $770 million US.

The sale from a multi-day auction includes more than 6,000 patents Ã¢ÂÂ" the last of Nortel's technology assets.

The patent portfolio touches nearly every aspect of telecommunications, including internet search and social networking.

The sale is subject to Canadian and U.S. court approval which will be sought at a joint hearing expected to be held July 11.

Nortel's court protection from creditors had earlier been extended to Dec. 14, to give the company more time to complete the sale of its assets and other restructuring efforts.

"The size and dollar value for this transaction is unprecedented, as was the significant interest in the portfolio among major companies around the world," said George Riedel, Nortel's chief strategy officer.

Nortel had previously announced it did not expect its shareholders to receive any value from its creditor protection proceedings.